
public class TestDemo {
    public static void main(String[] args) {
        int a;
        //System.out.println(a);
    }
    public static void main6(String[] args) {
        byte b1=10;
        byte b2=20;
        //byte b3=b1+b2;
        byte b4=10+20;
    }
    public static void main5(String[] args) {
        //byte b1=128;//err 超出范围必报错，java很严格
        byte b2=127;

    }
    public static void main4(String[] args) {
        String s="123";
        int a=Integer.valueOf(s);
        System.out.println(a);
    }
    public static void main3(String[] args) {
        int a=Integer.MAX_VALUE;
        Long b=10L;
        System.out.println(a);
    }
    public static void main1(String[] args) {
        for(int i=0;i<args.length;i++) {
            System.out.println(args[i]);
        }
        System.out.println("Hello World!");
    }

    public static void main2(String[] args) {
        int a = 10;
        int b = 20;
        System.out.println("a:"+a+b);// a:1020
        System.out.println(a+b+"haha");// 30haha
    }
}
